This invention relates to container wrappers, and more particularly to container wrappers including tear strips for facilitating the opening of the wrapper. The invention also relates to methods and apparatus for making such wrappers with tear strips, to containers employing such wrappers with tear strips, and to methods and apparatus for making such containers.
Although the invention will be described in the illustrative context of outer wrappers for certain kinds of cigarette boxes, it will be understood that the invention has numerous other applications, and that the invention is not limited to use in the described context.
One popular type of cigarette packaging is the so-called "flip-top box". This is a cardboard box, the upper portion of which is partially cut at an angle so that the top portion of the box can be pivoted up and to the rear to allow the cigarettes to be removed. In particular, the front of the box is cut across at a predetermined distance down from the top, and each side is cut across from the adjacent end of the front cut up to a point at the rear which is substantially closer to the top than the front cut. This means that the cuts in the side walls are not parallel to the top and bottom of the box, but rather are inclined up toward the rear of the box. Stated another way, the plane defined by the front and side wall cuts is oblique (rather than perpendicular) to the vertical axis of the box (i.e., the axis to which the front, rear, and side walls are substantially parallel).
In order to help keep the contents of such boxes fresh, it is customary to wrap the box in an outer wrapper, which is usually a polypropylene film or web. To facilitate removal of this outer wrapper, a tear tape is typically included on the inner surface of the outer wrapper in the vicinity of the abovementioned cuts (which form the parting line between the pivotable upper portion of the box and the remaining lower portion) The tear tape extends annularly around the box in a plane perpendicular to the vertical axis of the box. To open the box, the tear tape is pulled out away from the box. This tears the polypropylene web and allows the web and tear tape to be removed and discarded. The upper portion of the box can then be pivoted up and to the rear as described above.
Recently, there has been increasing interest in reducing the amount of refuse associated with the use of cigarettes. For this purpose, it would be desirable if most or all of the polypropylene outer wrapper could be made to stay with the box after the box had been opened This can be done by such expedients as heat shrinking or otherwise adhering the outer wrapper to the box. Then, when the tear tape is pulled, only the tear tape and the immediately adjacent annular portion of the outer wrapper come off. The upper and lower portions of the outer wrapper remain adhered to the box The problem with this is that, because the tear tape is disposed in a plane perpendicular to the vertical axis of the box, while the parting line between the upper and lower portions of the box defines a plane oblique to that axis, the remnants of the outer wrapper tend to interfere with subsequent opening of the box.
In view of the foregoing, it is an object of this invention to provide improved outer wrappers for containers of the type described above.
It is a more particular object of the invention to provide outer wrappers having tear tapes which conform to the parting line between the parts of the container to which the outer wrapper is applied.